Apparatus for dressing grinders



-May 5, 1925.

A. L. CURRIER APPARATUS FOR DRESSING GRINDERS FiledFeb. 19, 1920 I N VEN TOR A TTORNEY.

, ployed in shop practice, and it has become Patented May 5, 1925.

rum EDI, STAT PATENT OFFICE.

ABTHUR L. Gunmen, on NEW rrswrorr, NEW HAMPSHIRE, assreivon "r0 J. w. MOORE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, a CORPORATION OF MASSA- APPARATUS son nnnssnve GRINDERS.

To all whom it may] concern:

a citizen of the United States, and resident of New Ipswich, inbthe county "of Hillshoro and State of New-Hampshire, have invented an Improvement in Apparatus for Dressing Grinders, 'ofwhich the'following description, in connection with'the accompanying drawings, is'a specification, likelettersfon the drawin s re aresentm like y b a:

parts. h My present invention is an I improved grinding wheel dressing or trueing apparatus and a method of performing the dressing operation. The use "of grinding.

wheels, for sharpening edge tools, cutters, or other work, is now very generally emimporta-nt tov dress, reform, clean and true up. the working surface of such grinding wheels. In the .use of a grinding wheel, such for example. as an emery or carborundum ,grlnder, the operat ng-surface or face .of the abrasive mater al becomes qulckly filled or cloggedby the material on which the grinder 1s used. hurthermore,-n1 the J usual operation ofsuch a grinding tool it is worn unevenly on its face and consequentlyl requires a constant dressing or trueing to restore its even grinding surface, as well as to clean and clear theabrasive inthe grinding surface. As the abrasive of such grinding tools is extremly hard, it is difficult tosecure a suitable dressing. material which will not be quickly worn away, it now being customary tojuse a. diamond. dresser. My present invention. contemplates the trueing and dressing of such a. grinding toolby a novel method and by employing an inexpensive abrasive, such as carborundum,"

emery or the like similar to that of which the grinding wheel itself 1S formed: Furtheremore, my invention utilizes a novel principle whereby the rotation of the grind ing wheel itself will produce a rotative action in the dressing apparatus, so arranged and, positioned as to effect a slanting, angular, eccentric, slashing or shearing cut on. thegrinder. This feature of a shearing cutting action between the dressing tool [and the grinder, is most important, as it cut abrasive surface.

Application filed Iehrua rylS, 1920. Serial No. 359,869.

1 automatically trues and trims the entire sur- Be t known that I, ARTHUR'L.' CURRIER,

the abrasive face of the grinder, removing the filling, if any, and effectually leaving the face of the, grinder with a clean, clear, sharp In the prior use of a diamond cutting tool, the abrasive surface was broken off and not left uniformly clean, clear and shar 3, whereas in employing my method and with the dresser herein shown and disclosed, I am'enabled to produce an ideally sharp reformed and trued abrasive "face on the grinder.

Additional features are that the .clearand sharp cutting actlon on the grinder is produced by an inexpenslve material, viz.,

carborundun'l or the like; that the relative motion between the grinder and the dresser is effected by the rotary action of the grinder itself, no belts, pulleys or the like being necessary to actuate'the dressing tool; the arrangement, position and operation of the dresser and grinder produce the desired relative action which effects the trueing and sharp cutting; and my novel dressing tool or apparatus isltself malntalned with a true surface for subsequent dressing of grinders,

and may be in a form which will give long life and, great wear to the dresser itself; the dressing tool medium being preferably mounted for rotative action in a convenient holder and on an anti-friction thrust hearing.

Referring to the drawings, illustrating my novel method and showing a preferred form of dressing tool,

Fig. 1 is a view partly in cross section of the dressing tool,

Fig.2 isa fragmentary plan'vi ew show ing the application of thedre'ssing tool to a grinding wheel;

' Fig. 3 is a'fraginentary cross-sectional view illustrating the-action of thedresser 2l11(lg1'lIlCl61;Z1Dd' Fig. 4 is an end viev showing the dress ing tool in cross-section as applied to a grinchng wheel; 7

It will be appreciated that my dressing tool may be, of any size desired and may be mounted other than as ahan'd apparatus So long asthe dressing tool is applied to the grinding wheel to be dressed in accordance with my method, and to effect a shearing cut, retrueing action and the like, my method is carried out. Thus the dresser might be mounted on amovable arm to be swung into and out of positionsimilar to the jointing tools on a planing machine, the resulting method of action on the grinder being the same as if the dressing tool is applied by hand. As illustrated in the drawings, a grinding wheel is mounted at 1, and the dressing tool at 2. The grinder may be of any desired size and width, being herein illustrated in characteristic proportions. The grinder 1 may be of emery, carborundum or stone, mounted for rotative action as indicated by the arrows 3. Such grinders are usually set in machine shops and power supplied through a pulley or other means rotating the axle of the grind ing wheel 1. The dresser tool 2 is preferably formed as a cylinder, and with its edge face 4 positioned or applied to the circumferential face 5 of the grinding wheel 1, eccentrically of the axial center of the dressing tool 2. lVith this method of application between the two surfaces 4 and 5 and with the grinder 1 rotating and the dressing tool 2 rotatable, a rotation of the tool 2 is imparted to it by the rotating action of the grinder 1, the dressing tool being thus automatically rotated in the direction of its arrow 6. As clearly shown in Fig. et, the resulting action of my method effects a slashing cut on the surface 5 of the grinder, this relative slanting cutting action preserving both surfaces 4 and 5 .in prime cutting con dition, and ftlltllQlll'lOlO automatically trueing the contacting surfaces of both grinder and dresser and maintaining these surfaces in the desired plane perpendicular to the radius of rotation of each implement.

The dressing tool itself is preferably mounted to rotate freely, and to be held in contact with the grinder as long as desired. As herein shown, the dressing tool 2 is of considerable length, thus giving a relatively long life and wearability thereto. I prefer to form the dressing or carborundum 2 as a cylinder, as shown, with a projecting flangelike portion 10 to aid in securing the same to a plate 11 having a central hub 12 of proper diameter to snugly fit within the circular recess of the flange 10. This enables a washer 13 of greater diameter than the hub 10 and of equal diameter to that of the cylindrical recess to be applied to the hub 12 and secured thereto by a screw let fitted into a tapped recess in the hub 12. I may also fit a cushion washer 15 between the contacting edge of the plate 11 and the abrasive 2. The plate 11 is secured to or formed with a shaft 16 extending into the handle portion. Preferably this shaft 16 is fitted within a tubular part 17 secured to the handle 18 and thus affording a long steady bearing for the rotation of the abrasit e 2. I prefer to mount the abrasive 2 on a bail bearing raceway, preferably as a thrust bearing between the hub 10 and plate 11, as indicated at 21, and a corresponding raceway 22, the latter mounted within a cup shaped portion 23 of the tubular handle part 17, as clearly shown in Fig. 1. A dust cap or guard 25 may be fitted over the ball bearing portions and secured at its rim by screws 26 to the outer rim part of the plate 11. The mounting just described enables the operator to hold the handle 18 and tubular column or portion 17, thus firmly positioning or alining the abrasive when applying to the grinding tool to be dressed. As soon as the surfaces 4: and 5 of the dresser and tool respectively are brought into contact at one side of the center of rotation of the dressing tool, the continued rotation of the dresser 1 will impart rotation of the grinder 2 and being mounted in a ball bearing this action will require but a minimum of power and makes the dressing tool immediately responsive to the rotating action of the grinder. The operator can move the dresser to and fro across the surface of the grinding wheel, so long as the points of contact are sufficiently at one side of the axis of the dresser to produce the rotation of the latter. Preferably and as herein shown, the dressing tool 2 is formed as a cylinder of sufficiently greater diameter than the surface 5 of the grinder to be dressed, so as to insure the dressing tool entirely covering the grinder surface 5, entirely at one side of the axis of the tool 2.

In operation, 1 find that the hardest. grinding wheel will be very quickly trued and reduced by the action of the dresser in offecting its shearing or slashing cut, this slanting or slashing cut preferably being efiiected by the contact of the grinding surfaces in a line outwardly from the center of the dresser, as clearly shown in Fig. 3, where the upper part of the cylindrical dressing tool 2 is that portion brought into contact with the grinder 1. Furthermore the continued action of the dresser leaves the surface of the dressing tool in sharp, clean and cutting form and ready for a subsequentopcration. The entire length of the cylindrical dressing tool member 2 may be used up in this action until the abrasive 2 is worn off or down to the washer 12 and even then may still be employed if the grinding wheel is of less width than the distance between the edge of the washer 13 and the outer surface of the dressing tool, in which case the washer 18 will not be an interfering obstruction.

My invention is further described and defined in the form of claim as follows:

A dressing apparatus of the kind described, comprising 111 tubularmember, a

handle secured to one end thereof an antifriction bearing mounted on the end of the 5) tube remote from the'handle, and a cylindrical abrasivedressing tool secured to the outer end of the anthfriction bearing,

the axes of the cylindrical dressing tool, tubular member, and handle being in alignment with each other. v 10 In testimony whereof, I have. signed my name to this specification.

ARTHUR L. OURRIER. 

